To tune yourself, you need a powrtuner with software (it's been discontinued but you can buy them 2nd hand) or HPtuner and software. Both require a laptop and a lot of reading and effort on your part. Otherwise you can order a canned tune from several companies. You basically buy the PCM and swap it with yours. Lastly, take it to a dyno who has the software to tune it for you.

Naturally the best is a dyno with a good operator. However, if you get a wideband to scan while scanning your car, you can do some awesome street tunes yourself.